Project(Summary( BACKGROUND: HIV.continues.to.be.a.pressing.public.health.challenge.in.the.United.States..Investment in HIV prevention research has resulted in several waves of evidence-based interventions. As.more.effective.interventions. emerge,.it.is.important.to.de-implement,.or.discontinue,.less.effective.interventions..Yet,.interventions.may.persist.if. they.are.well.integrated.into.the.organizations.that.provide.them..HIV.prevention.policy.revisions.by.the.Centers.for. Disease.Control.and.Prevention.(CDC),.which.have.recommended.different.evidence-based.interventions.over.time,. provide.an.ideal.context.to.examine.the.de-implementation.or.persistence.of.less.effective.interventions..Based.on. revisions.in.CDC.policy,.we.have.identified.20.interventions.that.are.less.effective.than.more.current.available. interventions..GOAL:.This.proposal.seeks.to.understand.the.extent.to.which.less.effective.interventions.are.de- implemented.in.practice.and.describe.the.processes.involved.when.de-implementing.an.intervention...AIMS.AND. METHODS:.This.is.a.two-stage.mixed-methods.study.that.integrates.quantitative.and.qualitative.approaches...Aim.1:.The. first.phase.seeks.to.assess.the.extent.to.which.less.effective.interventions.are.de-implemented.among.public.health. organizations.that.implemented.one.or.more.interventions.recommended.by.the.CDC...This.will.involve.a.survey.of.800. practitioners.in.public.health.organizations..Aim.2:.The.second.phase.seeks.to.describe.the.process.of.de- implementation.among.public.health.organizations.that.de-implemented.an.intervention..This.will.involve.12.in-depth. case.studies.with.a.variety.of.public.health.organizations.and.interventions...Organizations.that.report.having.de- implemented.an.intervention.will.be.recruited.and.will.involve.interviews.with.four.organizational.staff.and.archival. document.collection.from.each.organization..Data.from.each.stage.will.be.analyzed.separately.and.then.synthesized.to. provide.complementary.insight.into.de-implementation..The.project.will.convene.a.strong.interdisciplinary.research. team.and.be.guided.by.an.External.Advisory.Board.with.the.scope.of.expertise.needed.to.successfully.complete.the. project..INNOVATION.AND.IMPACT:.This.study.is.innovative.and.impactful.because:.1).It.will.be.one.of.the.first.research. projects.addressing.intervention.de-implementation.in.public.health.and.perhaps.the.first.in.HIV.prevention,.key. priorities.for.the.National.Institutes.of.Mental.Health..2).This.work.has.the.potential.to.inform.successful.de- implementation.of.less.effective.HIV.prevention.interventions.?.freeing.limited.resources.and.infrastructure.to.support. more.effective.HIV.prevention.interventions.?.with.potential.application.to.other.areas.of.public.health.where.less. effective.interventions.persist.in.practice..3).The.mixed-methods.approach.and.empirical.data.will.provide.a.foundation. for.continued.research.in.this.area..